1. Technical Field
The present invention relates to a liquid crystal display, in particular, to a liquid crystal display including a backlight using fluorescent lamps.
2. Related Art
A liquid crystal display, accompanying a tendency of an increase in size of its liquid crystal display panel, often uses a direct-type backlight in which a plurality of linear light sources, or the like, such as external electrode fluorescent lamps (EEFL's) or cold cathode fluorescent lamps (CCFL's), are disposed on the same plane directly beneath the liquid crystal display panel.
Usually, with the backlight, a reflecting sheet or a reflecting plate is laid inside a metallic frame member, and a plurality of fluorescent lamps are disposed thereon. Power is supplied to both ends of the fluorescent lamps from a separately provided inverter circuit substrate, or power circuit including an inverter or the like.
The inverter circuit substrate and power circuit are usually disposed on the back surface of the frame member, and these substrates and both ends of the fluorescent lamps are connected by lamp cables. As an example showing this kind of structure, there is a patent document 1 (JP-A-2008-153217 (related U.S. Patent Application US2008/0143920A)).
In the heretofore known liquid crystal display, the lamp cables are wired outside the frame member, introduced into the inside of the frame member from positions close to the ends of the fluorescent lamps, and connected to both ends of the fluorescent lamps disposed inside the frame member.
On the other hand, as shown in a patent document 2 (JP-A-2003-68125 (related U.S. Patent Application (US2003/0016312A)), there is also an example in which a groove, in which lamps of a backlight are contained when wiring lamp wires through which power for the lamps is supplied, is provided in the top of a sidewall of a mold frame, and the lamp wires are disposed in the groove.
With the method of mounting the lamp cables outside the frame member, as in the patent document 1, it is necessary to secure a wiring space outside the frame member, and it is necessary to pay attention to a routing of the lamp cables outside the frame member. In particular, in a case in which the inverter substrate and power substrate are brought into one, as the length of the routed lamp cables also becomes greater, it becomes necessary to perform an assembly with more attention to an interference of the lamp cables with another circuit substrate, or the like. Also, in the kind of case of the patent document 2, as a special processing is needed for the mold frame (the frame member), a manufacturing cost increases, and it also causes an increased thickness of the sidewall of the frame. This affects a reduction in thickness and weight of the liquid crystal display.
Furthermore, in the case of the backlight of the EEFL's, electrode fittings on which the fluorescent lamps are connected in parallel, and the junctions of the lamp cables with the electrode fittings, usually have their conductive members exposed, requiring that a sufficient insulation property be secured between them and the metallic frame member. For this reason, forming an opening in the frame member in the vicinity of the electrode fittings and the junctions of the lamp cables with the electrode fittings, and introducing the lamp cables, also causes a reduction in the insulation property.